In the semiconductor industry, a trend has emerged where separate integrated circuit (IC) dies implement different functionality and are packaged together to form a System-in-Package (SiP). This may permit simplified semiconductor processing for each IC die and may permit higher yield by de-coupling semiconductor processing for separate IC dies. Further, different suppliers may provide the different IC dies. For example, one supplier may provide a memory die, while another may provide a processor die. In such situations, communications between the IC dies can present challenges.